Method of accelerating fruit ripening



United States Patent 3,499,750 METHOD OF ACCELERATING FRUIT RIPENINGGeolfrey E. Barnsley, Canterbury, Kent, Peter A.

Gabhott, Sittingbourne, Kent, and Barry V. Milborrow, Canterbury, Kent,England, assignors to Shell Oil Company, New York, N.Y., a corporationof Delaware N0 Drawing. Filed Mar. 6, 1967, Ser. No. 621,074 Claimspriority, application Great Britain, Mar. 4, 1966, 9,574/ 66 Int. Cl.A01n /00 US. Cl. 71113 5 Claims ABSTRACT OF THE DISCLOSURE Accelerationof fruit-ripening in plants by treating the plants at the time theplantis bearing fruit with 3,-methyl- 5-(1-hydroxy-4-oxo-2,6,6-trimethyl2 cycl0hexen-1-yl)- 2,4-pentadienoic acid.

In the field of horticulture, there has always been a need for new plantgrowth regulators. One such area has been for chemicals that acceleratethe ripening of commercially important fruit such as olives, cotton(bolls), nuts and the like.

While a chemical such as tributylphosphorotrithioite accelerates fruitripening to some degree, it is primarily used as a commercial defoliant,especially of cotton. While some degree of defoliation isunobjectionable in a fruit ripening agent, there are crops wheredefoliation is not needed. For example, in the growing of olives, thenormal harvesting operation involves beating the branches of the tree inorder to release the olives. This method causes severe damage .whichappears to seriously reduce the yield in subsequent seasons. Here aswith other crops, there is a need for an agent that will hasten theripening of fruit and not significantly alter other portions of theplant.

We have now discovered an agent, 3-methyl-5-(1-hydroxy-4-oxo-2,6,6trimethyl 2 cyclohexen-1-yl)-2,4- pentadienoic acid, that is highlyeffective as an accelerator of fruit ripening.

OBJECTS It is an object of this invention to provide a method ofaccelerating fruit ripening in plants. Another object is to provide amethod whereby the fruit ripening is accomplished with no or reduceddefoliation of the plant. Still another object is to provide a method ofhastening fruit ripening that uses a chemical that has a low mammaliantoxicity and leaves low levels of residue. It is yet another object toprovide a method whereby the time and labor involved during theharvesting of fruit is reduced.

STATEMENT OF THE INVENTION These objects are accomplished by a methodcomprising contacting fruit-bearing plants at the time the plant isbearing fruit with a biologically active amount of 3-methyl-5-(1-hydroxy-4-oxo-2,6,6-trimethy1 2-cyc1ohexen-1-yl)-2,4-pentadienoic acid.

A preferred class of fruit-bearing plants are the field crops and thosecommonly associated with orchards.

FRUIT-BEARING PLANTS AND FRUIT RIPENING AGENT The fruit-bearing plantsinclude not only what is popularly regarded as fruit, i.e., juicy ediblematerials such as apples, grapes, pineapples and the like, but alsothose substances that are considered fruits in the botanical sense,i.e., the matured ovary of a flower. This latter usage includes thefruit of cotton, corn, tomatoes and the like.

Field crops include cotton, peanuts, cabbage, peas, lettuce, onions,carrots, snap beans, cucumbers, spinach,

wheat, corn, rice, barley, and the like. As is evident, many of thesefruit-bearing plants are popularly called vegetables.

The term orchard plant includes those plants which produce what is bycommon usage considered fruit. This includes plants such as citrus(oranges, grapefruit, limes, lemons, etc.), grapes, apples, peaches,melons, peas, plums, apricots, cherries, strawberries, avocados,cranberries, bush berries, dates, figs, olives, persimmons, pineapples,nuts, such as walnuts, almonds, chestnuts. Most of the fruit comes fromtrees or shrubs.

The fruit-ripening agent, 3-methyl-5-t1-hydroxy-4-oxo-2,6,6-trimethyl-2-cyclohexen-lyl)-2,4 pentadienoic acid may exist in cisor trans configuration with respect to both double bonds in the carbonchain. Moreover, since there is an asymmetric carbon atom present in thecompound, optical isomers and racemic mixtures are possible. All isomersand mixtures are within the scope of the present invention. The compoundis described in an article by J. W. Cornforth et al. in Nature 206, 715(11965).

UTILITY The fruit-ripening agent is applied to the plant at the time thetree is bearing fruit. Preferably the flowering cycle has concludedbefore the fruit-ripening agent is applied.

Since the fruit-ripening agent is a solid under ordinary conditions andis needed in relatively small amounts, it is preferable to apply it inthe form of a solution or dispersion although any method that willassure an equal distribution is suitable. The fruit-ripening agent maybe applied in any of the conventional formulations used in theagricultural art for application to the aerial portions of the plant.Thus, the agent may be formulated with a carrier which may be a solid orliquid and may be of synthetic or natural origin to form a composition.Solid carriers may comprise clays, silicates, synthetic hydrated siliconoxides, resins, waxes, synthetic polymeric materials or elementalsubstances. Examples of liquid carriers are water, alcohols, ketones,aromatic hydrocarbons, chlorinated hydrocarbons, suitable petroleumfractions, and dimethylsulphoxide.

Surface active agents, stabilizers, fertilizers and/or certainbiologically active materials may be incorporated in the compositions ofthe invention. The compositions of the invention may be formulated aswettable powders, dusts, granules, concentrates, solutions, emulsifiableconcentrates or conventional emulsions.

When solution, emulsions, dusts, etc., are used as carriers in preparingformulations, the concentration of the accelerating agent is usually inthe range of 0.0001% by weight, preferably 0.01%50% by weight of theformulation. The concentration of the solution will depend somewhat onthe mode of application, i.e., spraying, immersion, dusting, etc., sincethe actual amount delivered to the plant varies with the mode ofapplication.

The minimum amount of accelerating agent necessary to accelerate theripening of the fruit is defined as a biologically active amount. Theparticular concentration for each variety of fruit-bearing plant willdepend on many conditions such as the particular plant, degree ofacceleration desired, mode of application, i.e., formulation used,weather conditions and the like. By the use of controls, for example,those skilled in the art can readily determine the optimum concentrationneeded to accelerate fruitripening for the particular plant.

Another reason for determining the optimum concentration of acceleratingagent for each plant is the tendency of the agent to acceleratedefoliation in plants. The de- Patented Mar. 10, 1970 foliation can,however, be kept to a minimum or insignificant amount by the use ofminimum concentrations of the accelerating agent needed for fruitripening. For example, the fruit-ripening agent of the inventionenhances the rate of ripening of cotton bolls at dosage rates which giveonly 4 and black) and the total weight recorded. On the 7th, 8th, and9th days the trees Were each given a light shake before collecting,grading and weighing. On the 10th, 11th and 12th days the trees weregiven a heavy shake before collecting, grading and weighing.Twenty-eight days after low levels of defoliation. Contrariwise,tributylphosphoro- Spraying all the olives remaining were collectedand/or trithioite, a commercial defoliant, requires dosages thatharvested to Obtain a measure of total yield per mm result in degrees ofdefoliation in cotton of about 90% to At no time during the trial werephytotoxic Symptoms achlqe slmllar npenmg effect as the agent of thlsfound on the leaves or fruit, but four days after applicai th th d f thtion the trees treated with 300 mg. and 600 mg. of 3- e CPmPOSItOHS 6lnven me 0 S methyl 5 1 -hydroxy 4- OX0 -2,6,6 trimethyl- 2 preparatlonand the invention concept of accelerating fruit ripening are allillustrated by the following examples. cyclohexen'l'yn '24'Pentad1en01cacld Suffered a mature leaf fall. This leaf fall did not, however, reachthe EXAMPLE I 15 proportions which were observed with the normalharvest- Preparation of a wettable powder ing Operations- 3 methyl s (1hydroxy 4 OX0 2,6,6 trimethyl- Should be 2?? E if fif f f if a? if i 2cyclohexen 1 yl) 2,4 pentadienoic acid Ion) g 1 2. 0 2 5 Tales w.),Tamol 731 3% w.), Empicol LZ 2% w.) and of Y W: F "tnme 20hexen-l-yl)-2,4-pentad1eno1c acid. Furthermore, at these Clay GTY (70%w.) (Tamol 731 is a polymethylacrylate anionic surfactant, Empicol LZ issodium lauryl sulphate; and Clay GTY is powdered hydrated aluminiumsilicate,

levels the degree of fruit ripening as evidenced by the fruit drop wasup to 4 times that of the control.

TABLE 1.WEIGI-IT OF OLIVE DROP AFTER TREATMENT Dose rate, mg./

Increase in Accumulative f h l- Increase in 5 i igigi i l ti leaf fallWeight of total weight leaf tall q e am. t t l weight compared witholive drop of olive compared with methyl-2-cyclo- Light Heavy of olivedrop control 12 collected 23 drop 23 control 28 hexen-l-yD-ZA- DropWithout shakshak- 12 days after day after days after y after y afte Plotpentadienoic shaking for 6 ing for ing for treatment treatment treatmenttreatment treatment No. acid days after 3 days 3 days 25th Oct, 25thOct. 5th Nov. 5th Nov. 5th Nov.

treatment 1 150 2 4 280 652 1 216 None 520 l 736 None. 2 200 {32 143 3 2'792 Some 360 1; 152 No further all since 25th Oct. 3 600 228 132 298658 Marked u 248 906 Some. 4 Control 110 60 142 312 306 618 a kaolinitechina clay) were blended and hammer milled, EXAMPLE V followed by airmilling and finally reblended to g ve a Acceleration of fruit ripeningand defoliation in mature wettable powder of small particle size. cottonEXAMPLE II Preparation of a wettable powder 3 methyl 5 (1 hydroxy 4 oxo2,6,6 trimethyl- 2 cyclohexen 1 yl )2,4-pentadienoic acid (50% w.),Tamol 731 (3% w.), Empicol LZ (2% W.) Florisil (22.5% w.), silicumdioxylol No. 3 (22.5% w.) (Florisil is attapulgite of Spanish origin andsilicum dioxylol No. 3 is a highly sorptive synthetic silicate) wereblended and hammer milled, followed by air milling and finally reblendedto give a wettable powder of small particle size.

EXAMPLE III Number of Days After Preparation of a solution TreatmentActive 5 8 11 21 23 2s 3 methyl 5 (1 hydroxy 4 0X0 tf lmethyl- Treatment(All Leaves Material, 2 cyclohexen 1 yl) 2,4 pentadienoic acid (10% ppp-p- Percentage Defohatlon W.), 'Itlerisiofix 1AdS (5% w.)1 TenglOfiXD1205 6) I- 2 213?l-5-(ig yidroxyi4ioxo- 1,288 21 5g 62 65 59 9; N-met y-pyrro i one/methy cyclo exanone to rime y olenen- 1 1 1 20 9 6 1-l-2,4- e tadienoic acid. 10 1 1 15 29 43 59 100% v.) (T ensiofix AS is amixed blend of two nonionic g g g 1,000 0 0 0 19 23 64 an so vent 1:1v.v. polyethylene condensates and an anionic alkylsulphonate, 60acetone/water) 0 0 0 0 3 6 12 Tensiofix D120 is an ethylene oxidecondensate with castor oil) were blended and dissolved in the solventmixture at a temperature of up to 40 C. maximum. The solution may befiltered where necessary.

EXAMPLE IV Fruit ripening of olives While this example demonstrates thatthe fruit-ripening agent of the invention may act as a defoliant,observations during the experiment showed that at comparable levels ofdefoliation, e.g., 3-methyl-5-(1-hydroxy-4-oxo-2,6,6-trimethyl-2-cyclohexen-l-yl)-2,4-pentadienoic acid at p.p.m. andtributylphosphorotrithioite at 1000 p.p.m. the 3-methyl-5-(l-hydroxy-4oxo 2,6, 6-trimethyl-2-cyclohexen-l-yl)-2,4-pentadienoic acid hadinduced a greater proportion of bolls to open, i.e., had accelerated theripening of the cotton fruit, at the 28th day of treatment.

EXAMPLE VI Thirty-five thirteen-year-old olive trees were selected fonif rmity of size, and grouped into 7 blocks each of 5 trees.

Within each block, the treatments were applied randomly and consistedof:

(i) Spray solvent only, onto 2 trees (ii) Spray solvent c0ntaini11g20mg. 3-methyl-5-(l-hydroxy4-oxo-2,6,6-trimethyl 2 cycloheXen-l-yl)-2,4-pentadienoic acid on 1 tree (iii) Spray solvent containing 60 mg.S-methyl-S-(l-hydroxy-4-oxo-2,6,6-trimethyl 2 cyclohexen-l-yl)-2,4-pentadienoic acid on 1 tree Using a knap-sack mist blower, each tree wastreated either with the spray solvent olen (consisting of 50 ml. ofacetone, 6 ml. Triton X-100 wetting agent, and 2000 ml. of water), orwith the appropriate solution of 3-methyl-5-(l-hydroxy-4-oxo-2,6,6-trimethyl 2-cyclohexen-l-yl)-2,4- pentadienoicacid in that solvent.

Treatment applications were made 3 weeks prior to the forecasted oliveharvesting date, and those olives which had dropped from the trees overthe period from Day 4 to Day 6 after treatment, were weighed. In theTable 3 below, the treatment mean weights of dropped olives are given.These mean weights have been adjusted to take into account the totalweights of olives on the trees at the time of spraying, and standarderrors of the means are given in parentheses, together with thestatistical significance of the difiference over the control whereappropriate.

TABLE 3 Treatment 3-methyl-5- trimethyl-2-cyclohexen-1-yl)-2,4-pentadienoic acid,

Moan wt. (in gms.) Collected Between 4th and 6th Day 0 i.e., blank spraycontrol 3-methyl-5-(l-hydroxy-4-oxo2,6,6-trimethyl-2-cycloheXen-l-yl)-2,4-pentadienoic acid was alsoapplied in a similar series of treatments at date 2 weeks and 1 weekprior to the expected harvest date, but the most significant resultswere those obtained from the 3 week application. However, the actualharvest was carried out about a week earlier than expected, andtherefore the results actually represent the effects achieved onspraying l and 2 weeks prior to harvest. Since the earlier applicationyielded the most significant increase in fruit drop, there is a clearpossibility that applications at an even earlier date would produce evenlarger eifects.

We claim:

1. The method of accelerating fruit ripening comprising contacting afruit-bearing plant at the time the plant is bearing fruit with aneffective amount of 3-1nethyl-5-(1- hydroxy-4-oxo-2,6,6-trimethyl2-cyclohexen 1-yl)-2,4- pentadienoic acid.

2. The method of claim 1 wherein the fruit-bearing plant is a fieldcrop.

3. The method of claim 1 wherein the fruit-bearing plant is an orchardplant.

4. The method of claim 3 wherein the orchard plant is an olive tree.

5. The method of claim 2 wherein the field crop is cotton.

References Cited Ohkuma et al., Science, vol. 142, pp. 1592 and 1593,1963.

JAMES O. THOMAS, 1a., Primary Examiner US. Cl. X.R, 71-70

